Release liners are often used in situations where it is desirable to deliver an adhesive backed article such as a label for subsequent use or application to another surface. In general, the adhesive backed article is applied to the release liner so that the adhesive on the article contacts the release surface of the release liner. The release liner can be peeled away from the adhesive backed article to allow the adhesive backed article to be used. Alternatively, the combination of the release liner and the adhesive backed article can be used. That is, the adhesive backed article and the release liner are commonly used together.
A release liner generally includes a substrate and a release surface. Exemplary substrates include films (e.g., vinyl) and polymer coated paper (e.g., polyethylene coated paper sometimes referred to as polycoated paper). The release surface can be formed on the substrate as a result of a coating composition that provides release properties when applied to the substrate. A widely used class of release coating compositions includes those based on silicone polymers such as polydimethylsiloxane polymers. Coating compositions based on polydimethylsiloxane chemistry are available as emulsions, solvent solutions, and as solventless materials. Friction coatings have been provided on polycoated paper to enhance the feed characteristics of the release liner in a printer. For example, the friction coating can assist with feeding the release liner and adhesive backed article through a printer.
Exemplary adhesive backed articles that are often used in combination with a release liner include labels. It is often desirable to print on the non-adhesive side of the adhesive backed article. Exemplary adhesive backed articles used in retail sales environments include those articles sometimes referred to as shelf markers, shelf talkers, drum labels, and hang tags. In general, shelf markers and shelf talkers are typically a type of label found in retail stores that identify a product on a shelf and sometimes include additional information such as price and sale information. The shelf marker or shelf talker can be provided as a combination of a release liner and a label. Alternatively, shelf markers and shelf talkers can be provided as labels peeled away from liners and adhered to a surface. In general, shelf markers and shelf talkers are not, themselves, attached to goods but are rather marking the shelf where the goods can be found. Hang tags can be similar but are often hanging from something such as a shelf or rack. Hang tags sometimes have an item to be sold attached to them. Hang tags can include a relatively rigid substrate having a label adhered thereto. A drum label is typically a label that affixes to the goods being sold. Hang tags and drum labels similarly includes printed information describing, for example, the price or conditions of sale of the goods.
For labels used in the retail store environment, it is often desirable to provide the labels with a relatively consistent graphic display, and allow the retail stores to add additional information, as desired. Accordingly, it is desirable to provide sheets of labels on release liners that can be feed through printing equipment such as ink jet printers and laser printers that can be found at retail stores.
A typical release liner can be provided as a polycoated paper substrate having a silicone coating on one side to provide release properties and a friction coating on the other side to enhance handling. A polycoated paper substrate refers to a substrate prepared from a paper base sheet having a thermoplastic polyolefin coated on both sides can be referred as polycoated release liners. Exemplary thermoplastic polyolefins used to coat paper base sheets include low density polyethylene and polypropylene. Polycoated release liners generally have good dimensional stability. That is, they exhibit low shrinkage, and have little tendency to curl. A drawback of polycoated release liners is that they tend to be expensive as a result of the polyolefin. Furthermore, they tend to lack desirable stiffness. An exemplary polycoated paper substrate used in the production of shelf markers, shelf talkers, hang tags, and drum labels in retail stores can be characterized as a substrate having a basis weight of about 92 lb/3,000 ft2. Such a product can be provided as a result of a paper base sheet having a basis weight of about 70 lb/3,000 ft2 and a polyolefin coating on each side of about 11-12 lb/3,000 ft2.